From BR Bullpen
Sean Christopher Marshall
- Bats Left, Throws Left
- Height 6' 7", Weight 205 lbs.
- School Virginia Commonwealth University
- High School Manchester High School
- Debut April 9, 2006
 Biographical Information
Pitcher Sean Marshall, twin brother of Brian Marshall, was 9-4 with a 3.34 ERA as a college freshman, winning rookie of the year honors in the Colonial Athletic Association. He also made Baseball America's second team freshman All-American team. In 2002, the sophomore was only 3-4 with a 4.45 ERA and outshone by his brother, the team's closer. In 2003, Sean went 7-2, 2.62 and was picked by the Chicago Cubs in the sixth round of the 2003 amateur draft. He was signed by scout Billy Swoope and made his pro debut that summer.
Marshall went 5-6 with a 2.57 ERA for the Boise Hawks, striking out 88 in 73 2/3 IP and then pitching 7 innings for the Lansing Lugnuts, striking out 11, walking none and allowing one unearned run for a victory. He was sixth in the Northwest League in ERA and picked as the NWL's #7 prospect by Baseball America.
In 2004, Sean was 2-0 with a 1.11 ERA in 7 starts for Lansing, allowing only a .171 average and 4 walks in 49 dazzling innings, striking out 51. Skipping a level, he went 2-2 for the West Tenn Diamond Jaxx with a 5.90 ERA and 1.66 WHIP in a major reversal of fortune. Baseball America rated him as the 9th-best prospect in the Midwest League and the 7th-best in the Cubs chain. For 2005, the tall left-hander had records of 4-4, 2.74 with the Daytona Cubs and 0-1, 2.52 for West Tenn. Baseball America picked him as Chicago's #6 prospect.
Marshall was 6-9 with a 5.59 ERA as a member of the 2006 Cubs rotation and he went 0-2, 3.32 in a brief stint with the Iowa Cubs. After spending 2007 as a starter with the Cubs, going 7-8, 3.92, he was a swingman in 2008 and 2009, making 7 starts the first year and 9 the second and pitching regularly out of the bullpen the rest of the time. He earned his first major league save in 2008 during a season in which he went 3-5, 3.86. On July 12, 2009, he was used in one game as a left fielder when manager Lou Piniella brought in righty Aaron Heilman to face one batter while Marshall was on the mound; after Heilman struck out Brendan Ryan of the St. Louis Cardinals, Marshall returned to the mound to finish the inning. He made the only postseason appearances of his career so far in the 2008 NLDS, being used twice in relief against the Los Angeles Dodgers and giving up a run in 3.1 innings.
In 2010, Marshall was a full-time reliever, pitching 74.2 inning in 80 appearances. He was 7-5, 2.65 as one of the most consistent performers out of the Cubs' bullpen. He had another excellent year in 2011, putting up a 2.26 ERA over 76 games and 75 2/3 innings, during which he struck out 79 while walking only 17. His record was 6-6 with 5 saves, but some measures of relief pitchers efficiency rated him as the third-best in the majors, behind Craig Kimbrel and Jonathan Papelbon, based on the number and quality of innings pitched out of the bullpen that season.
On December 21, 2011, Marshall was traded to the Cincinnati Reds in return for Travis Wood and two other players to be named, OF Dave Sappelt and IF Ronald Torreyes. On February 27, 2012, he signed a three-year contract extension worth $16.5 million.
Main sources: 2002-2006 Baseball Almanacs